Stress Analysis of Periodontal Tissue in en Masse Retraction With Integration of Maxillary Anterior Teeth: A Three-Dimensional Finite Element Method Study.

OBJECTIVE: To simulate the en masse traction technique with the integration (EMTI) of six maxillary anterior teeth using a finite element model (FEM) and explore various protocols for maxillary protrusion. The study aimed to investigate root displacement and stress distribution in the periodontal ligament (PDL) by varying the retraction position and direction of EMTI applied to the maxillary anterior teeth. No actual participants were involved. MATERIALS AND METHODS: The FEM model included six teeth (central and lateral incisors and canines) with a PDL thickness of 0.3 mm. The model encompassing the alveolar bone (ALB) and EMTI had 180,528 elements and 47,836 nodes. The EMTI integrated six anterior teeth via a 0.9-mm-diameter stainless steel lingual wire, equipped with three moment arms extending toward the root apex: one midline (central arm) and two distal to the canines (lateral arms). The position and direction of the traction force applied to the three moment arms of the EMTI were varied to assess crown and apex displacement, as well as PDL stress. RESULTS: Lingual tipping was consistent across all protocols, emphasizing controlled incisor tipping. The application of horizontal traction at 10 mm and traction at 7 mm from the central and lateral arms of the EMTI, respectively, demonstrated the most uniform stress distribution across the PDL of all six anterior teeth. CONCLUSIONS AND CLINICAL SIGNIFICANCE: The FEM analysis results suggest that the new EMTI method, which retracts the maxillary anterior teeth as a unit, is effective for tooth movement and PDL stress distribution. The EMTI technique, with its specific traction protocols and emphasis on controlled tipping, appears to be a promising approach for addressing maxillary protrusions.

Designing Novel Endodontic Implants and Evaluation of the Stress Distribution in Maxillary Anteriors Using Finite Element Analysis.

Introduction Endodontic implants, or didontic implants, offer a promising solution for stabilizing compromised teeth with a guarded prognosis and prolonging their clinical survival rate. Despite their potential benefits, they retired out of practice due to failures that arose from the lack of a biocompatible seal and engaging in dentin. Novel designs, based on evidence-based research with the help of bioceramics, present an opportunity to overcome these challenges and hence, enhance the clinical efficacy of endodontic implants. Thus the aim of this study is to design novel endodontic implants and evaluate their stress distribution in maxillary incisors using finite element analysis (FEA). Materials and methodology FEA is a biomechanical study to assess the stress distribution and extent of displacement to assess the clinical efficacy of novel endodontic implants in maxillary anterior teeth. Three 3D models (Model 1, Model 2, and Model 3) are designed to be meshed, and material elastic properties of the tooth and periapical tissues are applied. Boundary conditions were established, and a constant axial load value of 600 N was applied at a 45° angle. The FEA analysis was done under the loading conditions to assess the stress patterns for the three 3D models in comparison to the intact tooth on the ANSYS software (ANSYS Inc, Pennsylvania). Results FEA simulations revealed the distribution of stress within the tooth structure under functional occlusal forces, as Von Misses stresses were analyzed to assess the likelihood of material yielding and failure, which was comparable to that of an intact tooth. The maximum stress of deformation was as follows: intact: 1.7589e-5 MAX; Model 1: 3.3804e-6 MAX; Model 2: 2.638e-5 MAX; and Model 3: 2.1986e-5 MAX. The area of stress concentrations did not occur at the interface of the coronal or apical seal, which prevented catastrophic failures. Conclusion By leveraging advanced design principles and materials, these implants offer a promising alternative to traditional approaches, particularly in trauma cases with a poor prognosis for the survival of the teeth leading to loss of tooth. Further clinical studies are warranted to validate the efficacy and long-term success of these novel endodontic implants in diverse patient populations.

Cone-beam computed tomographic evaluation to estimate the prevalence of palatogingival groove in the maxillary anterior teeth and its radiographic characteristics: An institutional retrospective study.

Aim: The purpose of the study was to radiographically evaluate the prevalence of palatogingival groove (PG) in the East Indian population in the maxillary anterior teeth in different genders, its unilateral/bilateral presentation, classified based on its radiographic characteristics, to determine the prevalence of different types, which could help in future treatment planning. Study Design: The design of the study was a retrospective study. Materials and Methods: Analysis of 429 maxillary anterior teeth (144 central incisors, 145 lateral incisors, and 139 canines) in 72 cone-beam computed tomography scans was done (31 males and 41 females, mean age 27.3 ± 7.63). Demographic details of patients and characteristics of PG, i.e. location, extension, depth, and type, were recorded. The presence of alveolar bone loss and periapical pathology was noted. Results: An overall prevalence of PG was found to be 2.33% (n = 10), with PG being detected in 2 (1.388%) central incisors, 8 (5.51%) lateral incisors, and 0 (0%) canines. Eight of the patients had a unilateral presence, while one patient reported with bilateral presence, implying a significantly higher predilection of unilateral occurrence (P = 0.02). The prevalence was found to be higher in females (n = 8). The teeth were categorized as either having Type I (6 teeth), Type II (3 teeth), or Type III (1 teeth). Three of the 10 PGs were present in the mesial, six in the mid-palatal, and one in the distal portion of the palatal surface. Conclusions: The prevalence of PG in the maxillary incisors in this cohort is 2.33%. The maxillary lateral incisors are the most affected teeth. Unilateral presentation is more common.

[Trueness of different digital design methods for incisal guidance of maxillary anterior implant-supported single crowns].

OBJECTIVE: To compare the trueness of incisal guidance of implant-supported single crowns designed by patient-specific motion (PSM) with that designed by average-value virtual articulator (AVA). METHODS: The study had recruited 12 participants with complete dentition and stable incisal guidance. An intraoral scanner was used to scan digital casts and record two types of patient-specific motion (data only including protrusive movement, and data including protrusive movement and lateral protrusive movement). The lingual surfaces of the maxillary incisors which guided the protrusive movement was selected and elevated to create a reference cast. A maxillary central incisor of original casts was vir-tually extracted and implanted to generate a working cast. The Dental system software program was used to design implant-supported single crowns with the anatomical coping design method. The incisal guidance was designed by different methods. The incisal guidance in control group was designed by the average-value virtual articulator. The incisal guidance in experiment groups was designed by the patient-specific motion only including protrusive movement (PSM1) and with the patient-specific motion including protrusive movement and lateral protrusive movement (PSM2). The incisal guidance of prosthesis designed by these 3 methods were compared with the original incisal guidance in Geomagic Control 2015 (3DSystem, America). The measurements included: Average of positive values, ratio of positive area and maximum value reflecting supra-occlusion; average of negative values, ratio of negative area and minimum value reflecting over-correction; and root mean square reflecting overall deviation. RESULTS: Statistical data were collected using the median (interquartile range) method. The average of positive values, ratio of positive area and average of negative values of the PSM2 group were smaller than those of the control group [8.0 (18.8) µm vs. 37.5 (47.5) µm; 0 vs. 7.2% (38.1%); -109.0 (63.8) µm vs.-66.5 (64.5) µm], and the ratio of negative area of PSM2 group was larger than those of the control group [52.9% (47.8%) vs. 17.3% (45.3%)], with significant differences (P all < 0.05). The ratio of positive area [0.1% (7.0%)] and average of negative values [-97.0 (61.5) µm] of PSM1 group, were smaller than those of the control group, and the ratio of negative area [40.7% (39.2%)] of the PSM1 group was larger than that of the control group, with significant differences (P < 0.05). The average of positive values [20.0 (42.0) µm] and ratio of positive area of PSM1 group was larger than that of the PSM2 group with significant differences (P < 0.05). CONCLUSION: To establish the incisor guidance of implant-supported single crowns, compared with the average-value virtual articulator and the patient-specific motion only including protrusive movement, the patient-specific motion including protrusive movement and lateral protrusive movement is more conducive to reducing the protrusive interference of prosthesis and improving the occlusal fit.

Evaluation of the efficacy of injectable platelet-rich fibrin versus platelet-rich plasma in the regeneration of traumatized necrotic immature maxillary anterior teeth: A randomized clinical trial.

BACKGROUND/AIM: This study aimed at comparing the regenerative potential of injectable platelet-rich fibrin (i-PRF) (Group 1) and platelet-rich plasma (Group 2) scaffolds. MATERIALS AND METHODS: Twenty-three patients, aged from 9 to 24 years, having 24 immature traumatized necrotic maxillary anterior teeth, were enrolled. Teeth trauma was confirmed by patients' history. Preoperative three-dimensional scans were done. In the first visit, canals were irrigated with 1.5% sodium hypochlorite then medicated with calcium hydroxide. After 2 weeks, patients were randomly assigned into one of the treatment groups (n = 12). The platelet concentrate was applied after centrifuging 10 mL of autologous venous blood with respect to the centrifugation protocol for each platelet concentrate. Patients were recalled at 6 and 12 months posttreatment, during which clinical and radiographic examinations and assessment of pulp sensitivity were done. Three-dimensional scanning was done after 12 months. The increase in root length and decrease in root canal diameters were calculated at three canal levels. Statistical analysis was done using the paired t-test and the independent t-test. The significance level was set at p < .05. RESULTS: There was no statistically significant difference between both groups regarding the increase in root length, decrease in coronal and middle canal diameters and the response to the electric pulp tester. Group (1) showed significantly greater decrease in apical canal diameter than Group (2) (p = .008). CONCLUSION: I-PRF can be considered as a valid regenerative scaffold for clinical use and with regards to the easier preparation technique, it is more recommended than platelet-rich plasma.

Trueness of different digital design methods for incisal guidance of maxillary anterior implant-supported single crowns / 北京大学学报(医学版)

Objective:To compare the trueness of incisal guidance of implant-supported single crowns designed by patient-specific motion(PSM)with that designed by average-value virtual articulator(AVA).Methods:The study had recruited 12 participants with complete dentition and stable incisal guidance.An intraoral scanner was used to scan digital casts and record two types of patient-specific mo-tion(data only including protrusive movement,and data including protrusive movement and lateral pro-trusive movement).The lingual surfaces of the maxillary incisors which guided the protrusive movement was selected and elevated to create a reference cast.A maxillary central incisor of original casts was vir-tually extracted and implanted to generate a working cast.The Dental system software program was used to design implant-supported single crowns with the anatomical coping design method.The incisal guidance was designed by different methods.The incisal guidance in control group was designed by the average-value virtual articulator.The incisal guidance in experiment groups was designed by the patient-specific motion only including protrusive movement(PSM1)and with the patient-specific motion including protru-sive movement and lateral protrusive movement(PSM2).The incisal guidance of prosthesis designed by these 3 methods were compared with the original incisal guidance in Geomagic Control 2015(3DSystem,America).The measurements included:Average of positive values,ratio of positive area and maximum value reflecting supra-occlusion;average of negative values,ratio of negative area and minimum value re-flecting over-correction;and root mean square reflecting overall deviation.Results:Statistical data were collected using the median(interquartile range)method.The average of positive values,ratio of positive area and average of negative values of the PSM2 group were smaller than those of the control group[8.0(18.8)μm vs.37.5(47.5)μm;0vs.7.2％(38.1％);-109.0(63.8)μm vs.-66.5(64.5)μm],and the ratio of negative area of PSM2 group was larger than those of the control group[52.9％(47.8％)vs.17.3％(45.3％)],with significant differences(P all＜0.05).The ratio of positive area[0.1％(7.0％)]and average of negative values[-97.0(61.5)μm]of PSM1 group,were smaller than those of the control group,and the ratio of negative area[40.7％(39.2％)]of the PSM1 group was larger than that of the control group,with significant differences(P＜0.05).The average of positive values[20.0(42.0)μm]and ratio of positive area of PSM1 group was larger than that of the PSM2 group with significant differences(P＜0.05).Conclusion:To establish the incisor guidance of implant-supported single crowns,compared with the average-value virtual articulator and the patient-specific motion only including protrusive movement,the patient-specific motion including protrusive movement and lateral protrusive movement is more conducive to reducing the protrusive interference of prosthesis and improving the occlusal fit.

Long-term bone remodeling of maxillary anterior teeth with post-treatment alveolar bone defect in adult patients with maxillary protrusion: a prospective follow-up study.

BACKGROUND: Alveolar bone defects, particularly palatal bone dehiscence (PBD) and labial bone fenestration (LBF), occur frequently as a result of retraction of the maxillary anterior teeth. The study aims to explore the long-term bone remodeling of maxillary anterior teeth in adult patients with post-orthodontic treatment PBD and LBF. MATERIALS AND METHODS: The study includes 24 adult patients with maxillary protrusion (8 males, 16 females) who were treated with extraction of four first premolars and had alveolar bone defects (PBD or LBF) in maxillary anterior teeth following orthodontic treatment. Cone-beam computed tomography imaging measurements were obtained before (T1), after (T2) orthodontic treatment, and after at least 1-year removable thermoplastic retainer retention (T3). The maxillary anterior teeth with PBD or LBF at T2 were divided into the PBD or LBF groups, respectively. The labial and palatal alveolar bone height (ABH), alveolar bone thickness (ABT), and movement of maxillary anterior teeth were measured during retraction (T2-T1) and retention (T3-T2) periods. RESULTS: The incidence of PBD and LBF in maxillary anterior teeth significantly increased after orthodontic treatment and decreased during the retention period. In the PBD group, the palatal ABH of all maxillary anterior teeth significantly increased from T1 to T2 but decreased from T2 to T3. The ABT of the maxillary central incisor and canine significantly increased on the palatal side and decreased on the labial side during the retention period. In the LBF group, the labial ABT of the maxillary central incisor at the apical level showed a significant decrease from T1 to T2, followed by an increase from T2 to T3. In both groups, the maxillary central incisor showed significant labial movement, with a relative intrusion during the retention period. CONCLUSION: For adult patients with maxillary protrusion, the alveolar bone defect of maxillary anterior teeth caused by orthodontic retraction significantly improved during the retention period, indicating good long-term bone remodeling. Our findings suggest that a combination of spontaneous reorientation of maxillary anterior teeth and bone remodeling contributed to alveolar bone covering in these patients.

Efficacy of crown lengthening for restoration of maxillary anterior tooth defects.

OBJECTIVE: The appearance of the gingival tissue around the teeth is essential in the aesthetics of the anterior maxillary region of the oral cavity. Abnormalities in symmetry and contour can significantly compromise the appearance of the natural or restored dentition, so the outcome is highly relevant to treatment choice. This study evaluated the efficacy of crown lengthening for restoration of maxillary anterior tooth defects. METHODS: A total of 80 patients (87 affected teeth) diagnosed with maxillary anterior tooth loss in Ganzhou People's Hospital between May 2020 and August 2021 were retrospectively enrolled and divided into an experimental group or a reference group according to different treatment methods, with 40 cases in each group. The reference group received a post and core procedure, while the experimental group received crown lengthening plus a post and core procedure. Outcome measures included clinical efficacy, gingival periodontal-related indices, and dental aesthetics indices. RESULTS: Crown lengthening plus post and core procedure was associated with a significantly higher clinical efficacy (95.65%) versus post and core procedure alone (78.05%) (P<0.05). Postoperatively, the levels of probing depth (PD), plaque index (PLI), bleeding index (BI), and gingival index (GI) were lower in patients of the experimental group than those in the reference group (all P<0.05). Crown lengthening plus post and core procedure resulted in more Kay class I and II patients and fewer Kay class III and IV versus the post and core procedure alone (P<0.05). The position of gingival margin (PGM) and gingival recession (GR) of patients in the experimental group were higher than those in the reference group after operation (P<0.05). Logistic regression analysis showed that the morphology of broken ends, plaque control, hygiene habits, and smoking were influencing factors for maxillary anterior tooth defects (all P<0.05). Patients were more satisfied (97.50%) in the experimental group than those in the reference group (80.00%) (P<0.05). CONCLUSION: Crown lengthening improves the periodontal condition of patients with maxillary anterior tooth loss, reduces gingival sulcus bleeding, and improves dental aesthetics and patient satisfaction. Further clinical studies are required prior to clinical promotion.

Aging changes in maxillary anterior teeth in untreated individuals: an observational longitudinal study.

OBJECTIVE: The aging of the occlusion and tooth wears influence the smile design This study aimed at evaluating the aging changes of maxillary anterior teeth in nontreated subjects. METHODS: The sample comprised dental models of 23 subjects (13 male, 10 female) with normal occlusions, taken at 13 (T1), 17 (T2) and 61 (T3) years of age. The following variables were measured in the maxillary anterior teeth using digital dental models: crown width/height proportion, anterior view width, crown angulation, gingival and incisal steps between central/lateral incisors and central incisors/canines. Interphase comparisons were evaluated using repeated measures analysis of variance followed by Tukey tests or Friedman tests. Sexual differences were evaluated using t tests (P < 0.05). RESULTS: From 13 to 61 years of age, a decrease of crown width/height proportion (P = 0.008 and P = < 0.001, for the lateral incisor and canines, respectively) and mesiodistal angulation (P = < 0.001, P = 0.001 and P = 0.025 for the central incisor, lateral incisor and canines, respectively) of the maxillary anterior teeth were observed. The steps of the gingival margin and the incisal steps decreased with aging. CONCLUSIONS: From adolescence to late adulthood, untreated individuals with normal occlusions demonstrated changes in the maxillary anterior teeth that may impair the smile esthetics and attractiveness.

A CBCT Study of Labial Alveolar Bone Thickness in the Maxillary Anterior Region in a Teaching Hospital Population in the Eastern Province of Saudi Arabia.

BACKGROUND AND OBJECTIVES: Labial alveolar bone thickness in the maxillary anterior region is the key factor in the placement of implants. Differences in the thickness of the bone are reported among different ethnic groups. Thus, the present study was aimed at assessing labial alveolar bone thickness in the maxillary anterior region in the population of the eastern province of Saudi Arabia. MATERIALS AND METHODS: The six anterior teeth in each of the 186 CBCT sagittal images were analyzed at three points: Point A from the facial plate at the level of the bone crest to the coronal root third, Point B to the mid-root surface, and Point C to the apical third. Crest height (Point D) was measured as the distance from the CEJ to the alveolar bone crest. The analysis was done using SPSS version 20. A p-value of <0.05 was considered statistically significant. RESULTS: The bone thickness at any given point (Point A, Point B, or Point C) was less than the preferred bone thickness of 2 mm in all six teeth. The thickness was minimum at Point B, maximum at Point C, and intermediate at Point A. This difference was found to be statistically significant (p-value < 0.05). The crestal height (Point D) was less than 3 mm, and it was not statistically significant. Comparison of bone thickness on the right and left sides for any given point was not statistically significant except at Point A in the central incisor, where it was statistically significant (p-value = 0.035). Gender comparison of bone thickness showed no difference at Point A; however, at Points B and C, it showed statistical significance (p-value < 0.05). CONCLUSIONS: The alveolar bone thickness being <2 mm in the labial anterior region warns of the importance of the proper assessment of bone during implant placement to have a predictable outcome.

Management of Complex Crown Fractures: A Case Series.

Maxillary teeth are most vulnerable to fracture due to trauma. An effective treatment plan for an anterior teeth fracture not only improves function and appearance but also benefits the patient psychologically. The reattachment of the fragmented tooth is one of the best treatment methods for such condition. It is considered as a better treatment option because it is uncomplicated, aesthetic, and preserves the dental structure. To achieve a positive prognosis, patient cooperation and awareness about the treatment are essential. This article includes three case reports that illustrate the management of complex maxillary anterior teeth fractures wherein the reattachment of the fractured tooth segments was undertaken.

Measuring the Facial Plate of Bone in the Upper Anterior Teeth Utilizing Cone Beam Computed Tomography at King Abdulaziz University, Jeddah, Saudi Arabia.

Background and aim Radiographic assessment is an important diagnostic tool in dental practice.Cone beam computed tomography (CBCT) is among the most important imaging examinations. By providing multiplanar visualization of the maxillofacial region, CBCT enables practitioners to assess various conditions three-dimensionally. CBCT is utilized in different fields within dentistry, including oral and maxillofacial surgery, endodontics, orthodontics, periodontics, implant dentistry, and others. Having access to accurate 3D images is crucial in implant dentistry. This study aimed to measure the crestal bone height loss and facial alveolar bone thickness in the maxillary anterior teeth using CBCT to investigate its effect on surgical planning for dental implant placement in adult patients. Material and methods CBCT scans (N = 119) of adults, aged 18-65 years, with bilateral permanent maxillary anterior teeth present were included in this retrospective study. The mean alveolar bone plate thickness and crest bone height loss adjacent to the maxillary anterior teeth were measured and differences were examined. Results The results suggest that additional care and assessment of dental implant placement should be considered when replacing the permanent lateral incisors and canines. The frequency of fenestrations and dehiscence is higher in older adults. Possible management includes guided bone regeneration or "pink restorative solutions." Conclusion CBCT analysis to assess the bone morphology surrounding "hopeless" maxillary anterior teeth is important to ensure proper diagnosis and management, including the use of dental implants.

A technical report on the hamular technique for radiographing maxillary anterior teeth using a digital sensor.

OBJECTIVE: Obtaining an intraoral periapical radiograph of the maxillary anterior teeth can be quite challenging, especially in patients where a rigid digital sensor cannot adequately fit in the palatal vault. This technical report presents a periapical radiographic technique that places the sensor in the space surrounding the hamular notch to avoid the spatial restrictions of the hard palate, opening the possibility of parallel alignment of the sensor and the long axis of the tooth, perpendicular alignment of the tube-head to both, and a minimally distorted resultant radiographic image. METHOD: Four adult patients demonstrated the quantitative and qualitative features of this hamular technique (HT). A human skull demonstrated relative magnification and image quality. EXAMPLES AND RESULTS: While patient and equipment-specific, comparisons of magnification, distortion, and image quality illustrate the potential capabilities and limitations of the HT. The HT radiographs appeared to be less distorted than the variable-angle technique (VAT-a clinical approximation of the bisecting angle technique) but magnified 7.9-21.6%. A radiograph of an implant showed a 2.0% distortion over true aspect ratio. The HT radiograph from a human skull showed a slightly lighter and less sharp image than the VAT radiograph. CONCLUSION: Preliminary results showed that while the HT images were magnified, lighter, and less sharp that the VAT, they were diagnosable for caries. In all the HT images presented in this technical report, there was less distortion than comparable techniques. Notably, one HT periapical radiograph of a maxillary lateral implant showed virtually no distortion, suggesting that a nearly parallel projection was achieved using the technique. While further research is needed, this report shows that the HT has the potential to produce minimally distorted digital radiographs of anterior teeth in patients where the sensor cannot adequately fit into the palatal vault.

Analysis of Geometric Proportions on Maxillary Anterior Teeth for Esthetic Smile Design: An In vivo Study.

BACKGROUND AND OBJECTIVES: The maxillary central incisor is the dominant element of anterior dental composition and hence should be restored or replaced with proper proportion of width and length for better aesthetic results. However, the literature is not clear regarding verifiable guidelines for the determination of proportions of the teeth. The aim of this study was to investigate the existence and suitability of Golden Rectangle, Recurring Aesthetic Dental Proportion, and Golden percentage between the widths of maxillary anterior teeth in individuals with natural dentition, with the aid of digital photographs and computer analysis. MATERIAL AND METHODS: Frontal full-face digital photographs of the subjects (in smile) were made under standardized conditions using a digital camera and a tripod stand was used to place and orient the camera in the standardized position (camera was positioned 1 meter away from the patient; and the lens of the camera was adjusted at the patients' lip level). Imaging software (Adobe Photoshop CS5; Adobe Systems, Inc, San Jose, Calif.) was used to mark the anatomic landmarks and to digitally analyze the photograph. The entire process of proportion analysis was done by a single observer. RESULTS: The RED proportion was not found to exist between the six maxillary anterior teeth. The values suggested in the golden percentage were not applicable on the subjects of this study. However, a slight modification of these percentages can be adopted taking into consideration the ethnicity differences of the subjects in this study. The values obtained were 24%, 15%, 11% in males and 23%, 15%, and 11% in females. Golden rectangle concept can be used for choosing dimensions of maxillary central incisors which are esthetically pleasing. CONCLUSION: RED proportion is an unsuitable methods to relate the successive widths of the maxillary anterior teeth. The golden percentage theory seems to be applicable to relate the successive widths of the maxillary anterior teeth if percentages are adjusted taking into consideration the ethnicity of the population. Golden rectangle concept is suitable for choosing dimensions of maxillary central incisors which are esthetically pleasing.

Influence of different incision designs on bone increment of guided bone regeneration (Bio-Gide collagen membrane +Bio-OSS bone powder) during the same period of maxillary anterior tooth implantation.

Exploring the influence of different incision designs on bone increment of guided bone regeneration [Bio-Gide collagen membrane +Bio-OSS bone powder (carbonate apatite crystal extracted from bovine bones), Bio-OSS bone meal was placed on the surface of the bone defect and then covered with a Bio-Gide membrane to close the wound] during the same period of maxillary anterior tooth implantation. The 99 patients from the stomatology department were divided into 3 groups: small incision (N = 30, group A), wide incision (N = 39, group B), internal gingival sulcus incision (N = 30, group C). At the different time (immediately after surgery, 6 months, 12 months and 24 months), the width and height of labial bone at different implant margin (2 mm, 4 mm, 6 mm) has no significant difference in comparison of any two of the three groups (p > 0.05). The score of esthetic feeling in group A was significant higher than group C (P < 0.05). The PPD, the incidence of SH, BOP in group A were all significant higher than group B (P < 0.05). The PISm, PISd, PPD, the incidence of SH and BOP in group A were all significant higher than group C (P < 0.05). The PISm, PISd, PPD, the incidence of SH and BOP in group B were all significant higher than group C (P < 0.05). The three groups has no significant different on the influence bone increment. The soft tissue condition around the implant after surgery was better in internal gingival crevicular incision than others two incisions, large-scale incision better than small incisions.

Comparison of Mesiodistal Width of Maxillary Anteriors with Arch Form in Various Malocclusions: A Retrospective Study.

AIM: This study was conducted for evaluating and comparing the mesiodistal width of upper anteriors in different malocclusions and its relation with various arch forms. MATERIALS AND METHODS: In total, 60 subjects with different malocclusions were examined. Mesiodistal width was measured for the anterior teeth using digital vernier caliper. 3M Unitek arch form template and two-dimensional (2D) model were superimposed to find out primarily the relation of arch form in specific malocclusion to the sum the mesiodistal width of the maxillary of anterior teeth and secondarily the relation of sum of the mesiodistal width of the maxillary anterior tooth with different arch forms. RESULTS: The ovoid arch form was common in class I malocclusion with mean mesiodistal width of 50.43 mm. The tapered arch form was the common type in both class II and class III malocclusion with mean mesiodistal width of 49.96 and 45.15 mm, respectively. CONCLUSION: The mean of anterior mesiodistal width for Angle's class III individuals was 45.15 mm considerably less than that of class II subjects and class I subjects, which signifies that the tooth material was more in the anterior region of the subject of class I followed by class II and class III malocclusions. CLINICAL SIGNIFICANCE: The performed study presents various maxillary dental arch forms observed in various malocclusions (Angle's class I, class II, and class III). The ovoid and tapered arch forms exhibited the common occurrence, while the square form was the rarest.

Comparative evaluation of torque prescription of commercially available 018Roth and 022MBT PEA brands in maxillary anterior teeth.

BACKGROUND: Torque is an important component of preadjusted edgewise prescriptions to achieve ideal/optimum tooth position and more so in aesthetics sensitive maxillary anterior teeth. Thus, the need to audit available commercial brands of 018Roth and 022MBT was felt and in vitro analysis of eight brands namely 3M Unitek, Dentaurum, d-tech, IMD Medical, Libral Leone, Modern Orthodontics, Ormco and Ortho Organizer, was carried out. METHODS: The method involved perfect superimposition of two standardized images: one delineating facial axis of the tooth with stainless steel straight wire and other with full dimension arch wire engagement in bracket. The two images were superimposed and opacity of one of the images altered using Adobe Photoshop software to reveal the position of two wires. The angle obtained between two wires gave a direct read-out of torque expression. The comparison was statistically done with one-way ANOVA and Tukey's HSD test. RESULTS: In 018Roth group, IMD Medical did not show any significant difference from the standard while comparison independent of standard showed that IMD, Modern Orthodontics and Ormco were not significantly different from each other. In 022MBT group, IMD Medical, d-tech, 3M Unitek and Modern Orthodontics did not have statistically significant difference from and independent of standard. CONCLUSION: Significant variations from the standard values of both 018 Roth and 022 MBT exist in the market products and thus selection of product must be based on proper guidance in addition to clinical acumen/experience. Also the methodology provides easy to use, inexpensive set-up in the clinical settings.

Correlation of anterior overbite with root position and buccal bone thickness of maxillary anterior teeth: a CBCT study.

PURPOSE: To investigate the correlation of anterior overbite with the sagittal root position (SRP) and buccal bone thickness (BBT) of the maxillary anterior teeth. METHODS: Cone-beam computed tomography (CBCT) data of southern Chinese patients who underwent CBCT examinations between November 2016 and December 2016 were collected. The anterior overbite was the predictor variable while the SRP and the BBT at 4 mm apical to the cementoenamel junction (CEJ-4) and midpoint of the root of the maxillary anterior teeth were set as the primary and secondary outcome variables, respectively. All measurements were done by two calibrated examiners. Correlations between variables were analyzed by the Spearman's correlation coefficient. The significance level was set at P < 0.05. RESULTS: CBCT data of 146 patients (65 men and 81 women) with a mean age of 44.2 ± 13.4 years were analyzed, and of the 876 maxillary anterior teeth evaluated, 9.8% were presented with deep overbites. Most of roots of the anterior teeth (94.9%) were positioned against the buccal cortical plate, of which, in 63.8% of them the apex was not covered by bone along the long axis of the tooth. The mean BBT at CEJ-4 was 0.89 mm at the central incisor, 0.85 mm at the lateral incisor and 0.84 mm at the canine. The overbite was positively correlated with SRP Class I subtypes and the BBT at CEJ-4 (P < 0.05). CONCLUSION: Deep overbite was more frequently accompanied by bone fenestration in the anterior maxillary areas.

Analysis of esthetic factors and evaluation of esthetic perception for maxillary anteriors of dental students / 대한치과보철학회지

PURPOSE: This research is to investigate factors that affect dental aesthetics and analyze whether individual perception affects and difference of genders affects the esthetic factors. MATERIALS AND METHODS: Seventy dental students of Chonnam University aged from 25 to 35 years old without periodontal problems were included. Maxillary dental cast for participants were made, and standardized photo was taken with a digital camera. Maximum visual width and the position of gingival zenith of maxillary anterior teeth and maximum height of the maxillary central incisors were measured by a measurement program and the shape of central incisor was categorized. Questionnaire was conducted to evaluate esthetic perception. SPSS program was used to perform statistical analysis. RESULTS: The average visual width ratio of right maxillary anteriors was 1.38:1:0.78 and 1.41:1:0.81 for the left which differ from the golden ratio. The width to height ratio for right and left central incisor was 0.84 and 0.83 respectively. The gingival zenith position was determined to be: mostly, central incisors and canines were located in the distal side, lateral incisors were located in the center. The visual width ratio of right maxillary anterior teeth, ratio of width to height of central incisor, gingival zenith position, crown morphology and amounts of gingival exposure upon smiling were not significantly different between genders, and facial patterns and these dental esthetic factors were not related to aesthetic perception. CONCLUSION: Even though participants had the visual width ratio of maxillary anteriors or ideal width to ideal height of central incisors that did not agree with the golden ratio, they had high satisfaction for dental esthetics. Esthetic perception depends more on subjective judgements of participants than objective indices.

Correlation between Interalar Distance and Mesiodistal Width of Maxillary Anterior Teeth in Thrissur, Kerala, Indian Population.

AIMS AND OBJECTIVES: The aim of this study was to assess the validity of interalar distance as an aid in maxillary anterior teeth selection in Thrissur, Kerala, Indian population. The study also evaluated whether interalar distance and maxillary anterior teeth undergo any changes as age increases in this population and whether there is a gender difference in these parameters in this population. MATERIALS AND METHODS: A study was planned on 1200 participants in Thrissur Municipal Corporation area, Kerala, India, with the aim of checking the validity of interalar distance as a successful aid in maxillary anterior teeth selection. The collected data were analyzed using SPSS version 21.0. Mean standard deviation and 95% confidence intervals were estimated. Student's t-test was used for comparison between gender and two age groups such as 18-25 and 40-50 years. One-way ANOVA analysis was done for combined effects. RESULTS: The study showed that there is a high statistical significance between the interalar distance and the mesiodistal width of six maxillary anterior teeth in females (P < 0.01) and no significance in males. CONCLUSION: The study concluded that, within the population evaluated, there was a high significant correlation between interalar distance and the mesiodistal width of six maxillary anterior teeth in both males and females. Both interalar distance and mesiodistal width of maxillary anterior teeth showed a significant increase in size as age increases. There was a significant increase in size difference for males compared to females in relation to interalar distance and not for mesiodistal width of maxillary anterior teeth.